Day 2-Worksheets and a Quiz

Today was more of a learning day. We first went over what we would be covering in Unit 1 and how grading would be done. Then, we worked on worksheets which reviewed ionic and covalent bonds, where we found the number of protons, neutrons and valence electrons there are in various elements. We also had to draw Lewis Dot structures for different elements. After we finished, we took the oral quiz which we had prepared for the night before and also took a practice written quiz. Although the day was not packed with new information, it was helpful to review things we learned last year.

Day 1-Milk in Motion Lab

Today we did a lab involving milk in motion. We first watched a video showing how to do the lab for homework: First pour some milk into a dish, then add a few drops of food coloring, finally, add one drop of dish soap and observe as the food coloring dances around the dish. In class, we got into groups and had to find out why the milk reacted this way to the dish soap. My partner, Chris Jung, and I came up with the hypothesis that the milk reacted this way because the soap's bipolar characteristics reduce the surface tension in the dish, letting the food coloring drops flow freely across the surface of the dish. Since the soap is bipolar, one end of it reacts with the fat in the milk, and one end doesn't. To test this theory, Chris and I did two tests each with Reduced Fat 2% milk and Whole Milk. Both times, the Whole Milk's reaction was much faster and more violent, which backs up our theory that the soap was in fact reacting with the fat in the milk. To make sure, we both each did two more tests but this time a little different. We each had one dish with plain black coffee, and one dish with coffee mixed with 2% Reduced fat milk. My partner and I found that in the plain coffee, there was little or no reaction, but in the coffee/milk solution, sure enough the food coloring danced around on the surface of the dish.